JOURNAL OF SEPARATION SCIENCE
·
2015
·Vol. 38
·期 21
·3774-3780
·
IF 2.737
Fuyou Du,Xian Zheng,Lin Sun,Qun Qin,Lin Guo,Guihua Ruan
A polymerized high internal phase emulsion monolith was used as a novel sorbent for solid-phase extraction coupled with high-performance liquid chromatography and fluorescence detection for the determination of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline in environmental water samples. The polymerized high internal phase emulsion monolithic column was prepared by the in situ polymerization of the continuous phase of a high internal phase emulsion containing glycidyl methacrylate, styrene, and divinylbenzene in pipette tips, and then functionalized with iminodiacetic acid. The resulting monolith exhibited highly interconnected porosity and large surface areas, making it an excellent candidate as an solid-phase extraction sorbent for the enrichment of trace tetracycline antibiotics. Several factors affecting the extraction performance of polymerized high internal phase emulsion monoliths, including the pH of sample solution, the eluting solvents, the sample loading flow rate and volume, were investigated, respectively. Under the optimized conditions, the mean recoveries of oxytetracycline, tetracycline, doxycycline, and chlorotetracycline spiked in pond and farm wastewater samples ranged from 78.1 to 119.3% with relative standard deviation less than 15%. The detection limits (S/N = 3) of the proposed method were in the range of 51–137 pg/mL. This study demonstrated that the monolithic polymerized high internal phase emulsion would be promising solid-phase extraction sorbents in the extraction and proconcentration of trace analytes from complex samples.
研究领域:
分析化学
·
环境科学
·
药物残留检测
·
色谱技术
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样品前处理
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DOI
高影响因子
Vegetable Research
·
2024
·Vol. 4
·期 1
·
IF 0
Chenxi Ji,Sihui Guan,Chenxu Liu,Chao Yu,Zhuping Yao,Hongjian Wan,Qingjing Ye,Guozhi Zhou,Huasen Wang,Yuan Cheng
Chili pepper (Capsicum annuum L.) is highly preferred by consumers owing to its distinctive flavor. Volatile organic compounds (VOCs) significantly influences the aromatic characteristics of chili peppers, thereby impacting their overall fruit quality. The study of chili pepper aroma remains at a nascent stage, with a notable gap in the literature regarding the composition and metabolic regulation of volatile flavor compounds in fresh chili peppers. This study focuses on the pepper cultivar var 'Qujiao 5' with rich fruit aroma, using headspace solid-phase microextraction full two-dimensional gas chromatography time of flight mass spectrometry (HS-SPME-GC × GC-TOFMS) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) detection technology platforms to analyze the VOCs present in green ripe pepper. A total of 1,558 VOCs were successfully identified. Utilizing the HS-SPME-GC × GC-TOFMS method pinpointed 933 substances, whereas the HS-SPME-GC-MS approach detected 773 compounds. Moreover, the two methods together identified 150 substances. Through the meticulous analysis of relative odor activity values (ROAV), it was conclusively determined that Pyrazine, 2-methoxy-3-(2-methylpropyl)- and 2-Nonenal, (E)- serve as pivotal volatile flavor compounds in chili fruit. Through the analysis of sensory flavor characteristics of chili peppers, it was found that fresh chili peppers have the main aroma characteristics of fatty, green bell pepper, and green, while also possessing modified odors such as floral and sweet. This research undertook a thorough comparative analysis of two different detection methods. It also meticulously examined the compositional and sensory attributes of the pepper VOCs, providing an essential reference for subsequent studies on the development of pepper fruit flavor quality.
研究领域:
植物学
·
食品科学
·
分析化学
✓ 已验证
DOI
International Journal of Minerals Metallurgy and Materials
·
2024
·Vol. 32
·期 1
·111-118
·
IF 5.6
Wang Xiaoxiao,Huang Qingsong
Densely distributed coherent nanoparticles (DCN) in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously. All the routes to this end can be generally classified into the liquid–solid route and the solid–solid route. However, the formation of DCN structures in steel requires long processes and complex steps. So far, obtaining steel with coherent particle enhancement in a short time remains a bottleneck, and some necessary steps remain unavoidable. Here, we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field. Ti–Y–Mn–O particles had an average size of around (3.53 ± 1.21) nm and can be obtained in just around 180 s. These small nanoparticles were coherent with the matrix, implying no accumulated dislocations between the particles and the steel matrix. Our findings have a potential application for improving material machining capacity, creep resistance, and radiation resistance.
研究领域:
材料科学
·
冶金工程
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DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2016
·Vol. 218
·期 2
·1600422
·
IF 2.495
Hao Yuan,Qingming Ma,Yang Song,Matthew Y. H. Tang,Yau Kei Chan,Ho Cheung Shum
In this study, Janus droplets are fabricated by inducing phase separation of single-phase droplets made up of an aqueous two-phase system (ATPS). The resultant Janus droplets are highly monodisperse in structures and internal morphologies. Due to the affinity partitioning properties of ATPS, encapsulated ingredients can automatically partition into different compartments of the resultant Janus droplets. The use of biocompatible and cytocompatible ATPS also enables the encapsulation of enzymes and cells in the resultant droplets with their activity preserved at a relatively high level.
研究领域:
生物工程
·
材料科学
·
细胞生物学
✓ 已验证
DOI
高影响因子
BMC Ophthalmology
·
2023
·Vol. 23
·期 1
·1-9
·
IF 2
Kanclerz Piotr,Hecht Idan,Tuuminen Raimo
Purpose Precise ocular measurements are fundamental for achieving excellent target refraction following both cataract surgery and refractive lens exchange. Biometry devices with swept-source optical coherence tomography (SS-OCT) employ longer wavelengths (1055–1300 nm) in order to have better penetration through opaque lenses than those with partial coherence interferometry (PCI) or low-coherence optical reflectometry (LCOR) methods. However, to date a pooled analysis showing the technical failure rate (TFR) between the methods has not been published. The aim of this study was to compare the TFR in SS-OCT and in PCI/LCOR biometry. Methods PubMed and Scopus were used to search the medical literature as of Feb 1, 2022. The following
研究领域:
眼科
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生物医学工程
·
医学影像技术
✓ 已验证
DOI
高影响因子
Journal of Experimental Nanoscience
·
2012
·
IF 1.011
Zhongping Chen
The precursors used to prepare high-quality nanoparticles by high-temperature decomposition are expensive and toxic organometallic compounds. Fe(OH)3, an inexpensive and environmentally friendly iron-containing compound, is for the first time introduced to act as an precursor to generate monodisperse iron oxide nanoparticles. The obtained nanoparticles are characterised by transmission electronic microscopy, IR, XRD and vibrating sample magnetometer. Organic-soluble ferromagnetic rod-like and superparamagnetic dot-like nanoparticles with the size ranging from 12 to 25 nm are obtained in a nonpolar solvent by adjusting reaction parameters, such as surfactant concentration and reaction time. Water-soluble nanoparticles can be synthesised when a bipolar solvent is used instead of nonpolar solvent. The results show that Fe(OH)3 is a promising precursor for the high-temperature decomposition method.
研究领域:
材料科学
·
纳米技术
·
无机化学
·
环境科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Shuang Mu,Qin Ma,Yu Zhang,Xu Shen,Chunjing Liao,Xiangyu Zhang,Yusheng Ding,Shaoming Dong,Jinshan Yang
In this work, the Yb 2 Si 2 O 7 interphase was prepared on SiC fibers using the sol–gel method. The influence of sol concentration on the morphology of the interphase was discussed. After heat treatment in argon at 1200°C for 1 h, the Yb 2 Si 2 O 7 was grown in situ on the fiber surface, forming an interphase layer. Then, SiC f /Yb 2 Si 2 O 7 /SiC minicomposites were prepared by chemical vapor infiltration (CVI). The Yb 2 Si 2 O 7 interphase exhibited no changes throughout the high-temperature preparation process and maintained stability and compatibility with the fiber and matrix. The tensile strength of SiC f /Yb 2 Si 2 O 7 /SiC minicomposites with Yb 2 Si 2 O 7 interphase was significantly higher than SiC f /SiC minicomposites without interphase. The crack deflection, interfacial debonding, and fiber pullout were observed in the tensile fracture of the SiC f /Yb 2 Si 2 O 7 /SiC minicomposites.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 17
·期 38
·25525-25535
·
IF 4.493
Yuanyuan Zhou,Hui Tang,Peiyi Wu
Thermo-dynamic volume phase transition mechanisms of poly[oligo(ethylene glycol)methacrylate] (POEGMA) based microgels with poly(ionic liquid) (PIL) cross-linking moieties are investigated in detail on the basis of temperature-dependent Fourier transform infrared (FTIR) spectroscopy. The original FTIR data are further analysed by two-dimensional correlation spectroscopy (2Dcos) with the perturbation correlation moving window (PCMW) technique. It is observed that the content of hydrophilic PIL cross-linking structure strongly affects the temperature induced volume phase transition mechanism of microgels in which the less cross-linked microgel exhibits a sharp volume phase transition process while the highly cross-linked microgel presents a broad transition behavior. Peculiarly, the dehydration of C–H groups acts as the driving force for the whole phase transition process within the less cross-linked microgel network and cooperative response of chemical groups is identified. It is deduced that the hydrophilic PIL moieties develop polymer–water–polymer interactions with CO groups as CO⋯D2O–PIL hydrogen bonds emerge in the less cross-linked system. As regards the highly cross-linked microgel system, the phase transition process is driven by the disruption of hydrogen bonds between CO groups and water molecules while the response of C–H groups becomes insensitive. PIL moieties passively dehydrate following the dehydration of C–H groups on oligo(ethylene glycol) side chains and no hydrogen bond between CO group and IL–D2O association appears during the phase transition process.
研究领域:
高分子科学
·
软物质物理
·
生物材料
·
药物递送
·
智能响应材料
✓ 已验证
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2023
·Vol. 415
·期 26
·6399-6410
·
IF 4.3
Jiang Maoyuan,Hua Shiyao,Zou Liang,Wang Yitao,Li Peng
Huangqi Guizhi Wuwu decoction (HGWD), as a classical formula, has been used for thousands of years in China. In this work, a comprehensive strategy was proposed for characterizing the chemical profile of HGWD based on online two-dimensional hydrophilic interaction and reversed-phase liquid chromatography coupled with hybrid linear ion trap-Orbitrap mass spectrometry (online HILIC × RP-ESI/HRMS/MS n ). The compounds in HGWD were first separated by the combined use of an XBridge amide column (150 × 4.6 mm, 3.5 μm) and Accucore C18 column (50 mm × 4.6 mm, 2.6 μm). Modulation with assistant technology, including trap columns and online dilution, was optimized and developed to decrease potential analyte loss and improve the resolution of the system. Subsequently, the accurate mass was determined by high-resolution Orbitrap and MS n fragment data by a hybrid linear ion trap (LTQ). In total, 170 chemical constituents were unambiguously identified or tentatively characterized in both positive and negative ion modes. Our study demonstrated that the proposed online HILIC × RP system coupled to the LTQ-Orbitrap MS platform is an efficient analytical technique for characterizing the chemical profile of multicomponent systems.
研究领域:
分析化学
·
药物分析
·
中医药学
·
质谱分析
·
色谱分析
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 1
·475-487
·
IF 3.9
Ling He,Ling Pan,Wei Zhou,Maolin Chen,Qinzhao Zhang,Wenqian Pan,Peng Xiao,Yang Li
The interaction and infiltration behavior between typical calcium–ferrum–alumina–silicate (CFAS) and Yb 4 Hf 3 O 12 ceramics at 1300, 1400, and 1500°C for different duration times were investigated. At 1300°C, the CFAS melt first crystallized and then generated massive anorthite with high-melting point, reducing the wettability of CFAS melt and physically blocking CFAS penetration paths. As the temperature increased to 1400°C and 1500°C, the wettability of the molten CFAS correspondingly increases. A continuous reaction layer, composed of apatite, fluorite, and garnet, was formed over Yb 4 Hf 3 O 12 ceramic due to the penetration of CFAS melt. Furthermore, the infiltration rate of CFAS decreases with increasing corrosion time because of the barrier effect primarily derived from the as-mentioned continuous reaction layer.
研究领域:
材料科学
·
陶瓷材料
·
高温材料
·
无机化学
·
表面化学
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2019
·Vol. 29
·期 43
·1903017
·
IF 15.621
Yuyu Yao,Yu Zhang,Wenqi Xiong,Zhenxing Wang,Marshet Getaye Sendeku,Ningning Li,Junjun Wang,Wenhao Huang,Feng Wang,Xueying Zhan,Shengjun Yuan,Chao Jiang,Congxin Xia,Jun He
MOX (M = Fe, Co, Mn, Cr, Lanthanide, or Actinide metals; O = oxygen, X = F, Cl, Br, I), an emerging type of 2D layered materials, have been theoretically predicted to possess unique electronic and magnetic properties. However, 2D MOX have rarely been investigated. Herein, for the first time, ultrathin high-quality ytterbium oxychloride (YbOCl) single crystals are successfully synthesized via an atmospheric pressure chemical vapor deposition method. Both theoretical simulations and experimental measurements are utilized to systematically investigate the Raman properties of 2D YbOCl nanosheets. The experimentally observed E g mode at 85.53 cm −1 and A 1g mode at 138.17 cm −1 demonstrate a good match to the results from density functional theory calculations. Furthermore, the temperature-dependent and thickness-dependent Raman scattering spectra reveal the adjacent layers in YbOCl nanosheets show a relatively weak van der Waals interaction. Additionally, the polarized-dependent Raman scattering spectra show the intensity of A 1g mode exhibits twofold patterns while the intensity of the E g mode remains constant as the rotation angle changes. These findings could provide the first-hand experimental information about the 2D YbOCl crystals.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2014
·Vol. 10
·期 30
·5463-5471
·
IF 4.151
Nan Sun,Lijuan Shi,Fei Lu,Shuting Xie,Liqiang Zheng
The phase behavior of a kind of pseudogemini surfactant in aqueous solutions, formed by the mixture of sodium dodecyl benzene sulfonate (SDBS) and butane-1,4-bis (methylimidazolium bromide) ([mim-C4-mim]Br2) or butane-1,4-bis(methylpyrrolidinium bromide) ([mpy-C4-mpy]Br2) in a molar ratio of 2 : 1, is reported in the present work. When [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 is mixed with SDBS in aqueous solutions, one cationic [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 molecule “bridges” two SDBS molecules by noncovalent interactions (e.g. electrostatic, π–π stacking, and σ–π interactions), behaving like a pseudogemini surfactant. Vesicles can be formed by this kind of pseudogemini surfactant, determined by freeze-fracture transmission electron microscopy (FF-TEM) or cryogenic-transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). The mixed system of sodium dodecyl sulfate (SDS) with [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 was also constructed, and only micelles were observed. We infer that a pseudogemini surfactant is formed under the synergic effect of electrostatic, π–π stacking, and σ–π interactions in the SDBS/[mim-C4-mim]Br2/H2O system, while electrostatic attraction and hydrophobic interactions may provide the directional force for vesicle formation in the SDBS/[mpy-C4-mpy]Br2/H2O system.
研究领域:
化学
·
材料科学
·
胶体与界面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）